Abstract:

An airway adaptor includes: an airway case; and an expired gas guiding
portion which is connected to the airway case to introduce a respiratory
gas to the airway case. The airway case includes: a first respiratory gas
flow path in which the respiratory gas flows in a first direction; and a
second respiratory gas flow path in which the respiratory gas flows in a
second direction opposite to the first direction.

Claims:

1. An airway adaptor comprising:an airway case; andan expired gas guiding
portion which is connected to the airway case to introduce a respiratory
gas to the airway case, whereinthe airway case includes:a first
respiratory gas flow path in which the respiratory gas flows in a first
direction; anda second respiratory gas flow path in which the respiratory
gas flows in a second direction opposite to the first direction.

2. The airway adaptor according to claim 1, wherein the expired gas
guiding portion is detachably connected to the airway case.

3. The airway adaptor according to claim 1, whereinthe airway case
includes a first side face and a second side face which are opposed to
each other, anda carbon dioxide sensor is attachable to the first side
face and the second side face.

4. The airway adaptor according to claim 1, wherein the first respiratory
gas flow path and the second respiratory gas flow path are juxtaposed to
each other.

5. The airway adaptor according to claim 1, wherein one of the first and
second respiratory gas flow paths surrounds the other of the first and
second respiratory gas flow paths.

6. The airway adaptor according to claim 1, wherein a nose cup for
surrounding a periphery of nostrils is disposed on one of the expired gas
guiding portion and the airway case.

7. The airway adaptor according to claim 1, whereina part of the airway
adaptor is disposed on a nasal mask shell of a nasal mask in which
positive pressure ventilation is enabled, andthe airway case is projected
to an outside of the nasal mask shell.

8. The airway adaptor according to claim 1, wherein the expired gas
guiding portion is a nasal tube which is to be inserted into nostrils of
a living body.

9. The airway adaptor according to claim 1, whereinthe expired gas guiding
portion includes:a first guiding portion which guides the respiratory gas
from nostrils of a living body; anda second guiding portion which guides
the respiratory gas from a mouth of the living body.

10. The airway adaptor according to claim 9, wherein the respiratory gas
which is guided by the first guiding portion and the respiratory gas
which is guided by the second guiding portion are joined together in the
airway case or at an upstream side of the airway case.

11. The airway adaptor according to claim 1, whereina part of the airway
adaptor is disposed on a face mask shell of a face mask in which positive
pressure ventilation is enabled, andthe airway case is projected to an
outside of the face mask shell.

12. The airway adaptor according to claim 9, wherein the first guiding
portion is a nasal tube which is to be inserted into the nostrils of the
living body.

Description:

BACKGROUND OF THE INVENTION

[0001]The present invention relates to the shape of an airway adaptor for,
in carbon dioxide measurement for detecting and measuring the existence,
concentration, and the like of carbon dioxide in the respiratory gas
expired through the nostrils or mouth of the living body, guiding the
expired gas discharged through the nostrils or mouth of the living body,
thereby allowing a measurement relating to carbon dioxide in the expired
gas to be effectively performed. The airway adaptor is configured so
that, in the case where a carbon dioxide sensor is to be attached to the
airway adaptor, the operations of attaching or detaching the sensor can
be performed simply and easily.

[0002]For example, a related-art carbon dioxide sensor for detecting and
measuring the existence, concentration, and the like of carbon dioxide in
the expired gas discharged through the nostrils or mouth of the living
body is configured in the following manner (see JP-A-2003-315264). An
airway case is provided in which transmissive windows through which light
is transmitted are disposed on right and left side faces of an airtight
case that is formed in a cylindrical or box-like shape, respectively, and
openings for guidingly introducing the expired gas and leading the gas to
the outside are formed in the upper and lower faces or the like,
respectively. On the side faces of the airway case in which the
transmissive windows are disposed, a light emitting element and a light
receiving element are supported by supporting members, respectively while
being opposed to each other. Light which is transmitted through the
expired gas passing through the interior of the airway adaptor is
detected and measured.

[0003]In order to effectively introduce the expired gas discharged through
the nostrils of the living body into the airway case for attaching the
carbon dioxide sensor, the airway adaptor is configured so that one side
has nasal tubes which are to be inserted respectively into the two
nostrils of the living body, and the other side is connected to a hole
portion disposed in the airway case. The carbon dioxide sensor is
configured so as to be detachable from the airway case.

[0004]In the thus configured carbon dioxide sensor, the measurement object
is the expired gas discharged through the nostrils of the living body,
and therefore the nasal tubes are attached to the nostrils with using an
airway adaptor. Accordingly, the sensor can be applied also to a mask
which is configured as a mask for carbon dioxide measurement having a
nasal mask shell.

[0005]From this viewpoint, a related-art carbon dioxide nasal mask has
been developed, which, even when a gas is supplied at a high flow rate
from the outside into the mask, can correctly measure the concentration
of carbon dioxide, and which is configured so that oxygen or the like can
be forcibly supplied (see JP-A-2008-200061).

[0006]Namely, the carbon dioxide nasal mask disclosed in JP-A-2008-200061
includes: a nasal mask shell which has a close contact edge adapted to be
brought into close contact with the face so as to cover the nose, and the
interior of which configures a sealed space; an airway case which is
formed in a part of the nasal mask shell, which, in a state where the
nasal mask shell is worn, is positioned immediately below the nostrils,
thereby allowing the expired gas expired through the nostrils to be
introduced, which has an expired gas discharge port for discharging the
introduced expired gas, and which is used for detachably attaching a
carbon dioxide sensor to the outside of the nasal mask shell; an
introduction port for allowing a gas such as oxygen or air to be
introduced from the outside into the nasal mask shell; and a nasal tube
for ensuring a passage through which, in the nasal mask shell, the
expired gas that is introduced from the nostrils into the airway case is
guided to the airway case without being diluted by the gas arriving from
the introduction port.

[0007]In the thus configured carbon dioxide nasal mask, the expired gas
reaches the airway case through the nasal tube, and adequately escapes
into the nasal mask shell through the expired gas discharge port. Even
when oxygen or the like arrives at the introduction port disposed in the
nasal mask shell, therefore, accurate carbon dioxide measurement is
enabled without causing the expired gas from the nose to be diluted by
oxygen or the like which flows into from the introduction port. Since the
nasal mask shell is in close contact with the face in the close contact
edge, the oxygen or the like arriving at the introduction port can be
used for generating a positive pressure, and hence can be used in an
apparatus for CPAP (Continuous Positive Airway Pressure) or NPPV
(Noninvasive Positive Pressure Ventilation) therapy which is used in
treatment of a patient suffering from sleep apnea syndrome or respiratory
failure. Therefore, carbon dioxide measurement under positive pressure
ventilation which is hardly performed in the prior art is enabled.

[0008]In JP-A-2008-200061, the airway case which is disposed in the carbon
dioxide nasal mask, and which is used for attaching the carbon dioxide
sensor is formed as a part of the nasal mask, the Y-shaped nasal tube
which can be inserted into the nostrils is disposed in one end of the
airway case, and the other end is disposed so as to be opposed to an open
port disposed in the airway case. With respect to the thus configured
airway case, it is necessary to obtain a configuration arrangement where
the inlet and outlet for the expired gas are disposed so as to be opposed
to each other, and, in order to allow the introducing flow of the expired
gas to easily move, the whole airway case is housed inside the carbon
dioxide nasal mask.

[0009]As described above, the carbon dioxide nasal mask has a complex
design, and hence works such as assembling of a plurality of parts and
maintenance are required. When the mask and the airway case are made
detachable without causing air leakage, there arises a problem in that
the structure is complicated. Also in the case where the carbon dioxide
sensor is attached to the airway case, the sensor must be incorporated
inside the nasal mask, and there is a disadvantage in that the attaching
and detaching operations are cumbersome.

[0010]Moreover, the carbon dioxide nasal mask has a special shape which is
complexly designed, and hence is difficult to be produced. Therefore,
problems in production technique and cost remain to be solved.

SUMMARY

[0011]It is therefore an object of the invention to provide an airway
adaptor configured so that operations of attaching and detaching a carbon
dioxide nasal mask (or a carbon dioxide face mask), to and from an
expired gas guiding portion and an airway case are facilitated, the
airway case is configured so as to be projected to the outside of the
nasal mask (or the face mask), a hermetical configuration is formed in
which introduction and discharge of the expired gas passing through the
airway case can be surely performed inside the nasal mask (or the face
mask) without causing air leakage to the outside thereof, and a carbon
dioxide sensor can be easily attached to and detached from the airway
case.

[0012]In order to achieve the object, according to the invention, there is
provided an airway adaptor comprising:

[0013]an airway case; and

[0014]an expired gas guiding portion which is connected to the airway case
to introduce a respiratory gas to the airway case, wherein

[0015]the airway case includes: [0016]a first respiratory gas flow path
in which the respiratory gas flows in a first direction; and [0017]a
second respiratory gas flow path in which the respiratory gas flows in a
second direction opposite to the first direction.

[0018]The expired gas guiding portion may be detachably connected to the
airway case.

[0019]The airway case may include a first side face and a second side face
which are opposed to each other, and a carbon dioxide sensor may be
attachable to the first side face and the second side face.

[0020]The first respiratory gas flow path and the second respiratory gas
flow path may be juxtaposed to each other.

[0021]One of the first and second respiratory gas flow paths may surround
the other of the first and second respiratory gas flow paths.

[0022]A nose cup for surrounding a periphery of nostrils may be disposed
on one of the expired gas guiding portion and the airway case.

[0023]A part of the airway adaptor may be disposed on a nasal mask shell
of a nasal mask in which positive pressure ventilation is enabled, and
the airway case may be projected to an outside of the nasal mask shell.

[0024]The expired gas guiding portion may be a nasal tube which is to be
inserted into nostrils of a living body.

[0025]The expired gas guiding portion may include: a first guiding portion
which guides the respiratory gas from nostrils of a living body; and a
second guiding portion which guides the respiratory gas from a mouth of
the living body.

[0026]The respiratory gas which is guided by the first guiding portion and
the respiratory gas which is guided by the second guiding portion may be
joined together in the airway case or at an upstream side of the airway
case.

[0027]A part of the airway adaptor may be disposed on a face mask shell of
a face mask in which positive pressure ventilation is enabled, and the
airway case may be projected to an outside of the face mask shell.

[0028]The first guiding portion may be a nasal tube which is to be
inserted into the nostrils of the living body.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 is a front view showing a configuration example of an airway
adaptor of the invention.

[0030]FIG. 2 is a sectional view of the airway adaptor shown in FIG. 1,
taken along line A-A.

[0031]FIG. 3 is a perspective view showing an embodiment in which the
airway adaptor is applied to a carbon dioxide nasal mask.

[0032]FIG. 4 is a front view of the airway adaptor which is applied to the
carbon dioxide nasal mask shown in FIG. 3.

[0033]FIG. 5 is a sectional view of portions taken along line B-B of FIG.
4 and showing the configuration of the airway adaptor.

[0034]FIGS. 6A and 6B illustrate relationships between the configurations
of first and second respiratory gas flow paths, and the flow of the
respiratory gas in an airway case of the airway adaptor, FIG. 6A is a
diagram showing a configuration where the first and second respiratory
gas flow paths are juxtaposed, and FIG. 6B is a diagram showing a
configuration where one of the first and second respiratory gas flow
paths surrounds the other path.

[0035]FIG. 7 is a diagram showing a use state in the case where the airway
adaptor is applied to a carbon dioxide nasal mask.

[0036]FIG. 8 is a schematic view in the case where the airway adaptor is
applied to a carbon dioxide face mask.

[0037]FIG. 9 is a diagram showing flows of the respiratory gases from the
nose and the mouth in the case where the airway adaptor is applied to a
carbon dioxide face mask.

[0038]FIG. 10 is a diagram showing attachment of a carbon dioxide sensor
in the case where the airway adaptor is applied to a carbon dioxide face
mask.

[0039]FIG. 11 is a diagram showing a use state in the case where the
airway adaptor is applied to a carbon dioxide face mask.

DETAILED DESCRIPTION OF EMBODIMENTS

[0040]Next, embodiments of the airway adaptor of the invention will be
described in detail with reference to the accompanying drawings. In the
figures, the identical components are denoted by the same reference
numerals, and duplicated description will be omitted.

[0041]FIGS. 1 and 2 show a configuration example of the airway adaptor of
the invention, FIG. 1 is a front view, and FIG. 2 is a sectional view.

[0042]Referring to FIGS. 1 and 2, the airway adaptor of the invention is
configured by an airway case 10, and an expired gas guiding portion 20
which is communicatingly connected to the airway case 10 to guidingly
introduce the respiratory gas to the airway case 10. The airway case 10
and the expired gas guiding portion 20 are detachably configured.

[0043]The airway case 10 includes a joining portion 22 which is used for
communicating connection to the expired gas guiding portion 20, and is
configured so that transmissive windows 12 through which light is
transmitted are disposed on right and left side faces of an airtight case
that is formed in a cylindrical or box-like shape, respectively, and an
opening 15 for guidingly introducing the expired gas and discharging the
gas to the outside is formed in the upper face 14.

[0044]In the expired gas guiding portion 20, a Y-shaped nasal tube 23
which is to be inserted into the nostrils of the living body is disposed
in one side, and the other side is communicatingly connected to the
joining portion 22 which is formed so as to be communicatingly connected
to the opening 15 formed in the upper face 14 of the airway case 10 to
guidingly introduce the expired gas into the airway case 10.

[0045]The airway case 10 has a configuration where an expired gas
introducing passage 24 which is used for introducing the expired gas
guidingly introduced from the expired gas guiding portion 20, and which
functions as a first respiratory gas flow path, and an expired gas
discharging passage 26 functioning as a second respiratory gas flow path
which is formed so as to be juxtaposed with the expired gas introducing
passage 24 to discharge the expired gas introduced into the airway case
10, to the outside are disposed. The reference numeral 27 denotes a
discharge port of the expired gas discharging passage 26.

[0046]FIGS. 3 to 5 show an embodiment in which the thus configured airway
adaptor of the invention is applied to an outer edge portion of a nasal
mask shell constituting a nasal mask, FIG. 3 is a perspective view, FIG.
4 is a front view, and FIG. 5 is a sectional view.

[0047]In FIGS. 3 to 5, as the expired gas guiding portion 20 of the airway
adaptor, a nasal tube 23 which is to be inserted into the nostrils is
exemplarily shown. In this case, the expired gas guiding portion 20 is
requested to have a shape which can adequately guide the expired gas from
the nostrils to the joining portion 22, and not required to be the nasal
tube 23. For example, the portion may have a cup-like shape which covers
the nostrils.

[0048]The airway case 10 may be partitioned into at least two passages by
a partition wall 25 on the side of the opening 15 formed in the upper
face 14, one of the partitioned passages is formed as the expired gas
introducing passage 24, and the other passage is formed as the expired
gas discharging passage 26 (see FIG. 5).

[0049]For example, the airway case 10 may be structured so that the
expired gas flowing through the expired gas introducing passage 24 is
returned in the airway case 10 and flows through the expired gas
discharging passage 26 (see FIG. 6A). Alternatively, the airway adaptor
may have a configuration where one of the expired gas introducing passage
24 and the expired gas discharging passage 26 is placed in the periphery
of the other passage while being separated therefrom by a required
partition wall 25' (see FIG. 6B). In this way, it may be configured so
that one of the expired gas introducing passage 24 functioning as the
first respiratory gas flow path and the expired gas discharging passage
26 functioning as the second respiratory gas flow path surrounds the
other passage. Contrary to FIG. 6A, the expired gas introducing passage
24 may surround the expired gas discharging passage 26. As described
above, it is configured (set) so that the respiratory gas flowing through
the expired gas introducing passage 24 functioning as the first
respiratory gas flow path, and that flowing through the expired gas
discharging passage 26 functioning as the second respiratory gas flow
path flow in opposite directions.

[0050]In the embodiment, in the thus configured airway adaptor, a part of
the airway case 10 is fixedly placed on an outer edge portion 32 of a
nasal mask shell 30 constituting a carbon dioxide nasal mask M, and the
airway case 10 is connected to the outside of the outer edge portion 32
of the nasal mask shell 30 while the airway case 10 is projected from the
nasal mask shell 30 as illustrated (see FIGS. 3 to 5). As illustrated, a
nose cup 34 for surrounding the periphery of the nostrils of the living
body is fixedly placed on a part of the airway case 10 forming the
expired gas introducing passage 24 (see FIGS. 3 to 5).

[0051]In the embodiment, the discharge port 27 of the expired gas
discharging passage 26 of the airway case 10 is opened in the inner side
of the nasal mask shell 30. As shown in FIG. 4, a carbon dioxide sensor
40 can be detachably attached to the airway case 10 of the thus
configured airway adaptor so as to be opposed to the side faces in which
the transmissive windows 12 are disposed.

[0052]FIG. 7 shows a state where the carbon dioxide nasal mask M
configured by applying the airway adaptor of the embodiment is used on
the subject. In this case, the outer edge portion 32 of the nasal mask
shell 30 of the carbon dioxide nasal mask M butts against the periphery
of the nose in the face of the subject so as to surround the periphery,
the nose cup 34 is placed so as to surround a peripheral portion of the
nostrils, and the tip ends of the expired gas guiding portion 20 are
inserted into the nostrils, respectively. The nasal mask shell 30 is in
close contact with the face in the outer edge portion 32, and hence the
oxygen or the like arriving at an introduction port 2 can be used for
generating a positive pressure.

[0053]In this way, the expired gas discharged through the nostrils of the
subject is guidingly introduced from the expired gas guiding portion 20
to the airway case 10 through the expired gas introducing passage 24 of
the airway case 10. Then, the expired gas which is introduced into the
airway case 10 is discharged into the nasal mask shell 30 through the
discharge port 27 which is opened in the inner side of the nasal mask
shell 30 (see FIG. 5). The expired gas which is passed through the
interior of the airway case 10 as described above can be subjected to
detection and measurement of the concentration of carbon dioxide or the
like of the expired gas, by the carbon dioxide sensor 40.

[0054]Furthermore, another embodiment of the airway adaptor of the
invention in which the invention is applied to a face mask will be
described with reference to FIGS. 8 to 11.

[0055]FIG. 8 is a schematic view of a carbon dioxide face mask M2 in which
the airway adaptor of the invention is applied to a face mask for
covering the nose and the mouth. The carbon dioxide face mask M2 includes
a face mask shell 60 having an outer edge portion 61 constituting an
opening which allows the nose and mouth of the subjected to be covered.
The expired gas guiding portion 20 which communicates with the airway
case 10 is disposed in the face mask shell 60. The expired gas guiding
portion 20 is configured by a first guiding portion 50 which guides the
respiratory gas from the nostrils, and a second guiding portion 52 which
guides the respiratory gas from the mouth. Although a nasal tube is shown
as an example of the first guiding portion 50, the portion may be a
cup-like nose cup which covers the nose. A part of the airway adaptor is
fixedly placed on a tip end portion 62 in which the diameter is reduced
in a tapered manner with starting from the opening configured by the
outer edge portion 61 of the face mask shell 60, and the airway case 10
is projected to the outside of the face mask shell 60. Both the
above-described configuration including the face mask shell 60, and a
configuration from which the face mask shell 60 is omitted can be
commercially distributed.

[0056]FIG. 9 shows flows of the respiratory gas in the case where the
airway adaptor of the invention is applied to a face mask. The
respiratory gas 70 from the nose is guided through the first guiding
portion 50, and then mixed with the respiratory gas 72 from the mouth in
the joining portion 22 which is at the upstream (the upstream in the flow
of the expired gas) side of the airway case 10. The mixed respiratory gas
is passed through the expired gas introducing passage 24 to be guided to
the airway case 10, and then discharged into the face mask through the
expired gas discharging passage 26. Alternatively, the respiratory gas 70
from the nose and the respiratory gas 72 from the mouth are mixed with
each other in the airway case 10.

[0057]FIG. 10 shows attachment of a carbon dioxide sensor in the case
where the airway adaptor of the invention is applied to a face mask, and
FIG. 11 shows a state where the sensor is used for the subject. As seen
from FIG. 10, the carbon dioxide sensor 40 can be detachably attached to
the airway case 10 of the airway adaptor. As shown in FIG. 11, the sensor
is used while the outer edge portion 61 of the face mask shell 60 is
properly closely contacted with the face of the subject. According to the
configuration, it is possible to adequately detect and measure the
existence, concentration, and the like of carbon dioxide in the expired
gas discharged through the nostrils or mouth of the living body. The face
mask shell 60 is in close contact with the face in the outer edge portion
61, and hence the oxygen or the like arriving at the introduction port 2
can be used for generating a positive pressure.

[0058]Although the preferred embodiments of the invention have been
described, the invention is not restricted to the above-described
embodiments. For example, the formation of the expired gas introducing
passage 24 functioning as the first respiratory gas flow path and the
expired gas discharging passage 26 functioning as the second respiratory
gas flow path in the airway case 10 may be performed by, in place of the
disposition of the partition wall 25 as in the embodiment, any one of
various other configurations, as far as the passages are juxtaposed to
each other. In addition, various design changes may be made without
departing the spirit of the invention.

[0059]According to an aspect of the invention, in an opening through which
the expired gas passing through the airway case is introduced and
discharged, and which is disposed in the upper face of the airway case,
an expired gas introducing passage functioning as the first respiratory
gas flow path communicating with the expired gas guiding portion for
guidingly introducing the expired gas, and an expired gas discharging
passage functioning as the second respiratory gas flow path for
discharging the expired gas to the outside are juxtaposed to each other.
According to the configuration, the operations of attaching and detaching
the expired gas guiding portion, the airway case, and the carbon dioxide
sensor are facilitated, and, also when the adaptor is to be attached to a
carbon dioxide nasal mask, the operations of attaching and detaching the
carbon dioxide sensor can be easily performed.

[0060]According to an aspect of the invention, the configuration where the
expired gas guiding portion and the airway case are detachable can be
formed in a relatively simple manner, and, when the adaptor is to be
attached to a carbon dioxide nasal mask, only a part of the airway
adaptor is fixedly placed on the nasal mask. Therefore, a hermetical
configuration can be formed in which introduction and discharge of the
expired gas passing through the airway case can be surely performed
inside the nasal mask without causing air leakage to the outside of the
nasal mask.

[0061]According to an aspect of the invention, the nose cup for
surrounding a face part in the periphery of the nostrils of the living
body is fixedly placed on a part which forms the expired gas introducing
passage disposed in the airway case. Even under positive pressure
ventilation in CPAP or NPPV therapy which is used in treatment of a
patient suffering from sleep apnea syndrome or respiratory failure,
therefore, the nose cup can prevent the expired gas from the nose from
being diluted by oxygen or the like which is inspired under positive
pressure.

[0062]According to an aspect of the invention, the airway case is fixedly
placed on an outer edge portion of a nasal mask shell of a carbon dioxide
nasal mask, and the airway case is connected to the outside of the nasal
mask shell, whereby a hermetical configuration can be formed in which
introduction and discharge of the expired gas passing through the airway
case can be surely performed inside the nasal mask without causing air
leakage to the outside of the nasal mask. Therefore, the airway adaptor
can be easily applied to an apparatus for CPAP or NPPV therapy which is
used in treatment of a patient suffering from sleep apnea syndrome or
respiratory failure.

[0063]According to an aspect of the invention, the airway adaptor has the
airway case which is projected from the nasal mask. Even when the subject
wears the nasal mask, therefore, the carbon dioxide sensor can be easily
attached to or detached from the airway case.

[0064]According to an aspect of the invention, in the opening which is
disposed in the upper face of the airway case, the expired gas
introducing passage and the expired gas discharging passage are
juxtaposed to each other. Therefore, it is requested that only the airway
case is projected from the nasal mask. Accordingly, the airway adaptor
can be applied without exerting substantial influence on the structure of
an existing nasal mask. Consequently, the production cost of a nasal mask
which is to be simultaneously used can be suppressed, and the airway
adaptor can be applied to various kinds of nasal masks.

[0065]According to an aspect of the invention, the expired gas guiding
portion is configured by the first guiding portion which guides the
respiratory gas from the nostrils of the living body, and the second
guiding portion which guides the respiratory gas from the mouth of the
living body. Therefore, the respiratory gases from both the nose and
mouth of the living body can be controlled. Furthermore, the airway
adaptor can be applied also to a face mask which is widely used in
respiratory therapy and the like.